Ship Having a Bridge Comprising a Cavity with a Built-In Rotary Plate

ABSTRACT

A ship for laying flexible undersea lines at sea, the ship having a deck including a cavity receiving said turntable and a motor-driven device for rotating the turntable and fastened to the carrier structure of the hull of the ship, also known as the “hull girder”. The top face of the circular turntable does not project significantly above the plane of the deck that is juxtaposed therewith. The turntable presents attachment elements for attaching a modular storage and handling device for storing and handling flexible lines by winding and unwinding the flexible lines.

The present invention relates to equipment for loading, transporting,and laying flexible lines, such as flexible pipes or control umbilicalsincluding electrical cables and arranged on board floating supports inorder to be installed at sea.

The technical sector of the invention is more particularly the field ofinstalling lines resting on the sea bottom, and in particular includingrisers having flexible pipes for extracting oil, gas, or other solubleor fusible material or a suspension of mineral material from under thesea via an underwater well head and up to a floating support, in orderto develop production fields installed out at sea, off shore. The mainand immediate application of the invention lies in the field ofproducing oil at sea.

The flexible pipes used as production or service lines for conveyingliquid or gaseous hydrocarbons present great mechanical strength, inparticular against internal pressure, against traction, and againstflattening, and they are usually laid by means of winches or tractiondevices such as “caterpullers” (i.e. tensioners having crawler tracksfitted with shoes that clamp against the line and that move continuouslyin translation in order to entrain the line therewith), or indeed bycombining both winches and caterpullers.

The traction forces applied by such caterpuller devices on a flexiblepipe can be considerable when laying at great depth, and the compressionforces exerted by the shoes on the line must be high enough to avoid anyrelative slip between the shoes and the line.

A control umbilical includes one or more hydraulic lines and/or electriccables for transmitting power and/or information.

The lines referred to as “flexible pipes” are well known in the art andthey are described in standards documents published by the AmericanPetroleum Institute (API), and more particularly under the referencesAPI 17J and API RP 17 B. Such flexible pipes are manufactured and soldin particular by the supplier Coflexip France.

As a general rule, such flexible pipes comprise inner sealing layers ofthermoplastic material associated with layers that withstand thepressure inside the line, generally made of steel or of compositematerials. Such flexible pipes are constituted more particularly byassembling layers of tubular thermoplastic materials and strong layersof steel or of composite materials made in the form of spiral-woundstrips with touching turns inside the thermoplastic pipe in order towithstand internal bursting pressure, and associated with externalreinforcement over the thermoplastic tubular layer and likewise in theform of touching spiral-wound strips, but at a pitch that is longer,i.e. with a smaller helical slope angle, in particular lying in therange 15° to 55°.

In the present description, the term “undersea flexible line” is usedmore generally to designate a cable, an umbilical, or a pipe capable ofaccepting a large amount of deformation without giving rise to largereturn forces, and in particular a flexible pipe.

In the prior art, ships for laying flexible lines at sea are fitted withdevices for storing and handling said lines as described below withreference to FIG. 4. Most conventionally, a series of winches or drumsof horizontal axis have line portions wound thereon and are arrangedadjacent to one another in the longitudinal direction of the ship. Thevarious line portions are thus wound on a plurality of winches, eachhaving a horizontal cylinder between two vertical side plates. In thattype of prior art embodiment, the horizontal cylinder needs to presentstiffness in bending because the weight of the wound line is taken upentirely by the cylinder.

Furthermore, the weight of the line and of the winch including itsvertical side plates is transmitted in full to the motor drive for thedrum. This results in the winches necessarily presenting a plate sizeand a windable capacity in terms of line length that are limited,particularly when the diameter of the line is larger.

With flexible lines of large diameter, such conventional storage onwinches as shown in FIG. 4 is often not possible since the minimumradius of curvature of such a flexible line is very large, and inparticular may be as much as 5 meters (m) or more, thereby requiringdrums to be of very large size and therefore unsuitable for handling.

Thus, in practice, the diameter of the end plates does not exceed 5 m to10 m for a drum weighing 400 (metric) tonnes (t) to 500 t correspondingto portions of line presenting lengths of less than 10 kilometers (km)and in particular lengths of 1 km to 10 km for line diameters of 50millimeters (mm) to 300 mm, which is why it is necessary, when layinglines of great length and/or of large diameter, to make use of a largenumber of winches that are thus arranged adjacent to one another.

Finally, connecting together the various line portions in order toconstitute a complete line providing a bottom-to-surface connectionrepresents handling operations that are relatively difficult and lengthyto perform and that require the laying ship to be out of operation forlong periods of time, thus representing large costs.

Devices are also known for storing and handling flexible lines thatinvolve using “winch” type winder devices having a cylinder on which theline is wound that is vertical, with that type of device either beingplaced on the deck of the ship or else installed inside the ship,generally at the bottom of a hold. Nevertheless, under suchcircumstances, the fact that the bottom plate of the winch is arrangedhorizontally over the deck of the ship means that that plate receivesthe load in full and needs to be supported by a support and rotationdevice that must present a very high degree of stiffness so as to becapable, on its own, of withstanding compression forces and also bendingand/or twisting forces, since the plate constitutes a turntable thatneeds to be kept properly plane so that the winch can be rotated aboutits vertical axis in a manner that is stable and accurate; it is alsonecessary for said winch to be removable after it has been used in orderto release the deck of the ship for other operations.

Installing such equipment is difficult, since it requires the use ofpowerful hoist means given that the structure carrying the turntabletogether with said turntable presents a weight in the range 250 t to 750t, or even more under extreme circumstances. Thus, such equipment can beinstalled or removed only in a sheltered zone, generally in a port,thereby preventing the ship from being used for a period of four to fivedays, or even several weeks.

WO 2004/068012 describes devices for storing lines by winding them, sucha device comprising a circular turntable mounted over a bottomsupporting surface situated above the deck of the ship on which the linestorage device is installed.

In WO 2004/068012, the line storage device operates by winding in amixed carousel and rotary basket mode described in FIG. 4B, in which anumbilical 10422 of small diameter is wound in “basket” mode (in themeaning of the definition given in paragraph (e) below concerning astorage device of the invention), the umbilical being wound against acentral cylinder of the storage device, while a line 1044 of largerdiameter is wound in “carousel” mode (in the meaning of the definitiongiven in paragraph (b) below in the definition of the modular storagedevice of the present invention) outside posts or other retaining meansof the storage device.

Thus, given the fact that the line 10422 is wound in basket mode, thecentral cylinder is not covered by an end plate of diameter greater thanthe diameter of the cylinder. On the contrary, the top opening betweenthe central cylinder and the peripheral means 10406 for retaining theline 10422 is empty.

In contrast, a top plate 10408 is added to the tops of the windingsupport elements 10406 outside which and against which the line 1044 iswound in carousel mode.

In document WO 2004/068012, of necessity, the umbilical or the linewound in basket mode around the central cylinder must accommodate asmaller minimum radius of curvature and must therefore present a smallerdiameter.

The embodiment of the mixed storage device described in WO 2004/068012presents the drawback of requiring a central cylinder of larger diameterwhen the lines stored in basket mode are of large diameter, therebymaking the storage zone situated between said cylinder and the axis ofthe basket unusable, so the overall storage capacity is thus severelyreduced compared with the storage mode of the present invention. Inaddition, it is more difficult to perform winding in basket mode withlines or umbilicals of small diameter since winding is not performedunder tension and requires more accurate control that is therefore moredifficult to perform in order to form concentric turns all lying on acommon plane, particularly since the diameter of the line and thediameters of the turns are small.

EP 1 118 572 confirms the analysis given above about the difficulty ofwinding a multi-turn layer in basket mode, the layer comprising aplurality of concentric turns resting on a common plane and beingconstituted by a line of small diameter, as is required in basket mode.

In WO 2004/068012, EP 1 118 572, and WO 2009/129223 which describedevices for storing lines by winding on board a ship for laying thelines at sea and including a turntable or a bottom plate, said turntableor bottom plate of the device is situated over the deck of the ship.

The object of the present invention is to provide an improved noveldevice for storing and holding flexible line on the deck of a ship fortransporting such lines and for laying them at sea.

More particularly, the object of the invention is to provide a devicefor storing and handling flexible lines on board laying ships that makesit possible to perform operations of laying said flexible lines at seathat are longer, that can be laid more easily, and that can be laid morequickly; still more particularly, the object of the invention is to makeit possible to release the deck of the ship more easily and more quicklyonce the line-laying operations have been completed and to reinstall thedevice as required for a new line-laying operation, as easily and asquickly as possible and to do so with relatively small handling means,thus making it possible, where necessary, for handling to be performedon site.

To do this, the present invention provides a laying ship for layingflexible undersea lines at sea, the ship having a deck including acavity having arranged therein said circular turntable and amotor-driven support and rotation device for the turntable, the top faceof said turntable not projecting significantly beyond the level of theportion of the deck that is immediately juxtaposed (or adjacent)laterally thereto, the periphery of said turntable preferably cominglevel with said deck, said turntable being supported by and co-operatingin rotation with elements of the support and rotation device fastened tothe carrier structure of the hull of the ship within said cavity, saidrotary turntable presenting attachment elements on its top face andsuitable for releasably attaching accessories to a modular device forstoring and handling by winding and unwinding said flexible line(s),said accessories including at least winding supports extending in adirection ZZ′ perpendicular to and above said plane of the deck of theship, and preferably disposed circularly and symmetrically relative tothe central axis of ration Z₁Z₁′ of said turntable, said attachmentelements for said winding support elements preferably being distributedregularly on the top face of said turntable, and also preferablydistributed circularly and symmetrically at different distances from thevertical central axis of rotation Z₁Z₁′ of said turntable.

It can be understood that each portion of the top face of said turntabledoes not project significantly from the level of the portion of theplane of the deck that is adjacent thereto, i.e. the closest portion, ina direction that is perpendicular to said plane at said plane portion.

The term “carrier structure of the hull of the ship” is used herein tomean the structure that is also commonly referred to as the “hullgirder”, which structure serves to support the ship proper together withits load, both on the deck and in its hold, when the hull is subjectedto buoyancy thrust. In the manner known to the person skilled in theart, the hull girder has main transverse structural elements known as“frames” and secondary transverse and longitudinal structural elementsknown as “bulb profiles” together with longitudinal structural elementsin the form of “primary beams”, with the top portions of said structuralelements supporting the deck of the ship.

The term “deck of the ship” is used herein to mean the top wall of thehull girder, which top wall is made of thick sheet metal known as the“deck plate”. It is generally continuous from the stern of the ship tothe bow of the ship and towards the sides, from port to starboard. Thistop wall is substantially horizontal or possibly slopes a little fromand on either side of the middle longitudinal axis of the deck towardsthe respective sides of the ship. A running portion of the deck is thusconstituted by thick sheet metal plates secured to said transversestructural elements of the frame or bulb profile type and to saidlongitudinal structural elements situated under said deck plate.

It can be understood that in the present invention, the ship has a hullgirder that is configured during building of the ship so as to create asaid cavity that is suitable for receiving and supporting said turntableand its support and rotary drive device together with the load on saidturntable, in particular said device for storing and handling flexiblelines and the line(s) stored on said turntable.

A first advantage of the invention stems from the principle of having aturntable incorporated in a cavity in the deck, thus avoiding any needto remove the turntable, so the turntable can be left in placepermanently. This represents a considerable saving of time. Since saidturntable does not project significantly above the plane of the deck,and also since it includes releasable attachment means for a saidmodular storage and handling device, it is possible to install andremove said modular device of the invention much more easily and muchmore quickly than prior art devices for storing and handling flexiblelines, and to do so with very limited hoisting and handling means, thusmaking it possible under certain circumstances to perform this type ofoperation directly on site without any need to return to port.

Thus, by means of the device of the invention, the major portion of theweight of the equipment, i.e. the turntable and its motor drive, stayspermanently in place since they are permanently incorporated in thecavity in the deck of the ship and they require large weights to behandled only while said ship is being built or while said turntable andits support and rotary drive device are being incorporated in the cavityin the deck of the ship. Likewise, the rigid structure for supportingthe turntable that exists in the prior art is replaced by theload-carrying structure of the ship itself, possibly with localreinforcement, and thus remains permanently incorporated in the shiptogether with the device of the invention, and therefore does notrequire large weight to be handled except when building said ship orwhen incorporating said turntable and the support and rotary drivedevice within the cavity in the deck of the ship, said turntable and therigid support structure as they exist in the prior art possiblyrepresenting a total weight of 150 t to 750 t, or even more.

Also as a result of this permanent incorporation of the turntable andits rotary drive device within said cavity, the stiffness required ofsaid turntable is relatively small, since said turntable is onlyrequired to transfer the forces that result from the load it iscarrying, without any need also to transfer possible repeated twistingand/or bending forces as would be necessary if said turntable needed tobe capable of being handled and moved together with its support androtary drive device after each occasion it is used, as in the prior art.

More particularly, the carrier structure of said turntable comprises afloor incorporated in the hull girder and forming an integral portion ofsaid hull girder, constituting a downward setback of a substantiallycircular portion of the deck, said floor constituting the top wall ofthe hull girder within said cavity and performing a role that is similarto that of the deck plate in terms of the strength of said hull girder.

Preferably, said floor is secured to additional reinforcing elementswithin the cavity and that form integral portions of the hull girderthat is configured in such a manner that the hull girder is capable oftransferring the load constituted by said turntable, said support androtary drive device, and its load, and is capable of providing thestiffness required for supporting said turntable and its load.

In a particular embodiment, said carrier structure of the hull includesadditional reinforcing elements in said cavity, and said support androtation device within said cavity comprises at least:

-   -   a floor fastened to and supported by said additional reinforcing        elements of said carrier structure of the hull under said floor;    -   rotary guide elements preferably comprising wheels supported by        said floor and a rotary shaft supported by additional        reinforcing elements of said carrier structure of the hull under        said floor; and    -   a motor and rotary drive elements for driving the turntable        and/or said rotary shaft in rotation by actuating said motor,        the elements being supported by structural elements of said        carrier structure of the hull at the periphery of said cavity        and/or of said additional reinforcing elements of said carrier        structure of the hull in said cavity, said rotary drive elements        preferably comprising gearing. Said rotary drive elements may        also comprise wheels or belts.

The term “additional reinforcing elements” is used to mean structuralelements that are additional compared with the remainder of theload-carrying structure of the hull, and suitable for ensuring that theload-carrying structure of the hull in the cavity has the ability totake up the compression loads represented by the turntable and itsloading as transferred locally directly to the load-carrying structureof the hull of the ship in the cavity as a result of the support androtary drive elements of the turntable being fastened directly to theload-carrying structure of the hull. It is thus possible to make use ofmodular storage and handling devices of the invention that are of largecapacity and thus possibly to use lines that are of great length and/orof large diameter compared with modular devices supported by turntablesthat are fitted over the deck of a ship in which the hull girder is notspecially configured with a cavity and additional reinforcing structureswithin the hull girder for supporting the turntable, and withoutrequiring the support structure for the turntable to be put into placeon the deck in order to take up a fraction of the compression loads andin order to provide said turntable with stiffness, as applies in theprior art.

More particularly, said additional reinforcing elements of saidload-carrying structure of the hull supporting said floor within saidcavity comprise transverse frames that are lower but closer together inthe longitudinal direction of the ship and longitudinal beams that arelower but closer to one another in the transverse direction of the ship.

The term “releasable attachment” is used to mean that said accessoriescan be installed and then removed in order to make room above saidturntable.

It can be understood that said accessories are suitable for co-operatingwith said turntable to form a modular device for storing and handlingflexible line(s) by winding and unwinding said flexible line(s).

It can be understood that because said attachment elements can bepositioned at different distances from the vertical central axis ofrotation Z₁Z₁′ of said turntable, it is possible to attach said windingsupports thereon at various positions, thereby enabling a variety ofdiameters to be wound, depending on the positions of said windingsupports on the surface of the turntable.

More particularly, said attachment elements comprise grooves and/orpreferably threaded holes arranged radially and/or circularly, andpreferably regularly distributed over the entire surface of theturntable.

It is thus easy with very limited handling means to position saidaccessories so as to form winding supports that enable windings ofvarious diameters to be wound on the surface of the turntable. Saidgrooves are a known way of providing releasable fastening co-operationwith elements that co-operate with or that are incorporated in thestructural portions at the bottoms of said accessories and that aresuitable for sliding therein, such as cleats. Said holes are suitablefor co-operating to provide releasable fastening with rods that arefastened in or incorporated in the bases of said accessories.

The present invention thus provides a laying ship supporting a modulardevice for storing and handling flexible line by winding and unwindingflexible line, the ship comprising:

a) a said turntable supporting said accessories on its top face, whichaccessories are reversibly attached to said attachment elements, saidaccessories thus forming one or more winding supports extending in theperpendicular direction ZZ′ and above said plane of said deck of theship, said winding supports being arranged circularly and symmetricallyrelative to the central axis of rotation Z₁Z₁′ of said turntable on thetop face of said turntable; and

b) a spooler device comprising a flexible line guide and holder devicemounted on a second support element forming a post, a tower, or a gantryextending at least in a direction perpendicular to and above the deck ofthe ship in the proximity of said turntable and including motor-drivenmeans for moving a first flexible line portion extending between saidguide and holding device and said storage and handling device, andsuitable for enabling vertical and/or horizontal movement of saidflexible line portion relative to said second support element in orderto enable said flexible line to be spooled around and against saidwinding supports.

It can be understood that said deck includes, close to said turntable,at least one second attachment element for attaching at least one saidsecond support element.

In conventional manner, the term “spooling” is used herein to mean theaction of guiding said line that is being arranged in touching turns forwinding and unwinding purposes:

-   -   either by moving said line vertically synchronously with the        rotation of said turntable, said turns then being juxtaposed one        above another in superposed manner;    -   or else by moving said line horizontally synchronously with the        rotation of said turntable, said turns resting on a common plane        and having winding diameters that vary continuously since they        are spiral-wound, being juxtaposed concentrically one beside        another.

In a first variant embodiment, the device for storing and handlingflexible line is of the type known as the “carousel” type and comprises:

a) a winding support having a continuous wall in the form of a taperingor right central cylinder arranged coaxially about the axis of saidturntable, said cylinder being surmounted by a top circular plate at itstop and preferably having the same diameter as said turntable; and

b) a spooler device suitable for spooling said flexible line around andagainst said central cylinder in said “carousel” mode, comprising a linetraction device suitable for tensioning said first line portionextending between said traction device and the already-wound orstill-wound portion of line, said traction device preferably being acaterpuller, and means suitable for moving said tensioned first flexibleline portion vertically in such a manner as to keep it substantiallyhorizontal while it is being wound or unwound so as to enable the lineto be spooled in a plurality of coaxial layers of touching turns andenabling it to be unwound, said flexible line thus being wound or beingsuitable for being wound in “carousel” mode in a plurality of layerssuch that the turns of any one layer are helically superposed, thevarious layers forming juxtaposed coaxial cylindrical columns,preferably by moving the traction device vertically.

It can be understood that:

-   -   the turns of the first layer are applied against said cylinder        and present a smallest winding diameter, and the turns of the        second layer that are applied against the turns of the first        layer present a greater winding diameter, with the following        cylindrical layers being applied in succession against the        preceding layers and each presenting a greater winding diameter,        such that two turns of two juxtaposed layers present winding        diameters that are different; and    -   the first layer is preferably formed by spooling the line        upwards so as to superpose the turns successively one above        another from said turntable on which the first turn rests at the        bottom up to a top plate against which the top face of the last        turn on top comes to abut, while the second layer is made by        spooling downwards from the underface of the top plate until the        turntable is reached. This explains why it is necessary to        maintain tension in the line portion between the holder and        guide device and the already-wound or still-wound line portion        on the winding support, since otherwise not only would it be        impossible for the line to remain wound in stable manner, but it        would also be impossible to perform winding while spooling        downwards.

In this carousel mode of winding, a winding support is used thatpreferably has a wall that is continuous and in the form of a taperingor right central cylinder since the line needs to be spooled undertension and, if a plurality of post type winding supports distributedregularly around the circle were in use, it would run the risk ofsuffering excessive bending and in particular bending with a radius ofcurvature smaller than its minimum radius of curvature at its points ofcontact with said posts, thus running the risk of damaging the innerstructure of said flexible lines.

More particularly, for this carousel mode winding, the line may be woundin k=2 to 100 coaxial layers, each layer comprising l=2 to 100 turns,and preferably five to ten turns that are helically superposed.

In a second variant embodiment, the flexible line storage and handlingdevice is of the type known as the “rotary basket” type and comprises:

a) a plurality of winding supports in the form of inner posts arrangedcircularly and preferably symmetrically relative to the axis of rotationZ₁Z₁′ of said turntable or a tapering or right central cylinder arrangedon the axis with said turntable, and peripheral retaining elementsextending in the perpendicular direction ZZ′ above said deck of theship, being disposed circularly and preferably symmetrically relative tothe central axis of rotation Z₁Z₁′ of said turntable on the top face ofsaid turntable, and also preferably regularly distributed at theperiphery of said turntable;

b) a spooler device suitable for spooling said flexible line around andagainst said central cylinder or said plurality of inner posts in“rotary basket” mode comprising a line holder and guide device,preferably a caterpuller, and means suitable for moving the firstflexible line portion in horizontal translation in a transversedirection YY′ perpendicular to said vertical central axis of rotationZ₁Z₁′, the first flexible line portion extending in an inclined and inparticular curved position between said holder and guide device and thealready-wound or still-wound line, preferably by moving said tractiondevice horizontally so as to enable the line to be spooled as aplurality of superposed layers of touching turns and so as to enable itto be unwound, the flexible line thus being wound or being suitable forbeing wound in “rotary basket” type mode as a plurality of superposedlayers such that the turns in any one layer are juxtaposedconcentrically, lying on a common plane and presenting diameters thatincrease from the first turn pressed against the winding support(s) outto the last turn coming into abutment against said peripheral posts,said line portion extending between the holder and guide device and thealready-wound or still-wound line without being tensioned by said holderand guide device, which is held at constant height above the top ends ofsaid winding supports and said retaining posts.

It can be understood that:

-   -   the first layer is formed by placing it on the turntable and        moving said line portion progressively away from the central        cylinder (or the inner winding support posts) starting from a        first turn that is juxtaposed with said central cylinder and        going out to a last turn at the periphery of the turntable (“go        direction”); and then    -   the second layer is formed by laying the second layer on top of        the first layer, while moving said line portion in the opposite        direction (“return direction”), i.e. moving the line closer to        the central cylinder; and    -   so on in the go and return directions for moving the        not-yet-wound line portion for the following layers (or inner        winding support posts) from the first peripheral turn superposed        on the last turn of the preceding layer where it is stabilized        and held by said peripheral retaining posts going towards said        central cylinder, and so on in the opposite travel direction for        the not-yet-wound line portion for the following layer; said        movements of said line portion in the go direction (away from)        and then in the return direction (towards) the central cylinder        for spooling purposes being synchronized with the rotation of        the turntable.

Preferably, in the “rotary basket” type embodiment, said inner postsforming said winding support elements and also said peripheral retainingposts are connected together in particular by respective circular railsat their tops. Furthermore, in this “rotary basket” type embodiment, thespace between said retaining elements and the central cylinder or saidwinding support elements does not include a top plate that wouldobstruct the passage and prevent proper winding/unwinding of saidnon-tensioned first line portion against said support elements, insofaras said first line portion is not arranged horizontally, but is inclinedfrom the holder and guide device towards said winding support elementssituated below said central cylinder, and insofar as said first lineportion must be capable of being moved in horizontal translation in saidspace.

In the present description, the term “circularly arranged” is used tomean that said elements are arranged along a circle, and in particularwhen referring to posts, that the bases and the tops of said posts arearranged along respective circles.

More particularly, in basket mode, a line is wound over m=2 to 100superposed layers, each layer having p=1 to 50 turns, and preferably 5to 20 coaxial touching turns.

In a preferred third variant embodiment of the invention, the flexibleline storage and handling device is of the mixed carousel and rotarybasket type and is suitable for storing and handling two flexible lines,the device comprising:

-   -   a first winding support for a first line, said first winding        support having a continuous wall in the form of a tapering or        right central cylinder arranged coaxially about the axis of said        turntable;    -   a plurality of second winding supports for winding a second        line, the supports being in the form of inner posts arranged        circularly and preferably symmetrically relative to the central        axis of rotation Z₁Z₁′ of said turntable at a constant radial        distance from said central cylinder, and also preferably        distributed regularly along their said circular line of        positioning on said turntable;    -   peripheral retaining elements in the form of posts extending in        the perpendicular direction ZZ′ above said plane of said ship        deck, arranged circularly and preferably symmetrically relative        to the central axis of rotation Z₁Z₁′ of said turntable and also        preferably distributed regularly at the periphery of said        turntable;    -   said central cylinder being surmounted by a top circular plate        at its top and of diameter such that said inner winding posts of        the second line are secured to one another at their tops by        being fastened to the periphery of said top plate, said first        and second support elements and said retaining elements being        arranged on the top face of said turntable;    -   a spooler device including at least a second support element for        supporting at least one flexible line guide and holder device        suitable for enabling a said first flexible line portion to be        moved vertically and/or horizontally, the first flexible line        portion extending between the guide and holder device and the        already-wound or still-wound line for spooling said flexible        line around and against said winding supports, said second        support element forming a tower or a gantry extending at least        in a direction ZZ′ perpendicular to the plane of said and above        said bridge, in the proximity of said turntable;    -   a said flexible guide and holder device being suitable for        enabling a first flexible line to be spooled around and against        said central cylinder in “carousel” mode and comprising a line        traction device suitable for tensioning the first line portion        extending between the traction device and the already-wound or        still-wound first line, said traction device preferably being a        caterpuller, and means suitable for vertically moving said first        flexible line portion extending between the traction device and        the already-wound or still-wound first line so that it can be        tensioned and held substantially horizontally by said traction        device to enable the first line to be spooled as a plurality of        coaxial layers of superposed touching turns, said first flexible        line thus being wound or being suitable for being wound as a        plurality of coaxial layers such that the turns in any one layer        are superposed helically, the various layers forming juxtaposed        coaxial cylindrical columns such that two turns of two        juxtaposed layers present different diameters; and    -   a said flexible line guide and holder device also being suitable        for enabling a second flexible line to be spooled around and        against said winding supports in the form of inner posts in        “rotary basket” type mode, comprising a device for holding and        guiding the line, preferably a caterpuller, and means suitable        for moving said portion of the second flexible line in        horizontal translation in a transverse direction YY′        perpendicular to said central axis of rotation Z₁Z₁′, said first        portion of the second flexible line extending in an inclined and        in particular curved position between the holder and guide        device and the already-wound or still-wound second line in order        to enable said second line to be spooled as a plurality of        superposed layers of touching turns, said second flexible line        thus being wound or being suitable for being wound as a        plurality of superposed layers such that the turns in any one        layer are concentrically juxtaposed, resting on a common plane        and having diameters that increase from the first turn pressed        against said winding supports in the form of inner posts to the        last turn coming into abutment against said peripheral retaining        posts, said first portion of the second line not being tensioned        by said holder and guide device, which is held at a constant        height above said winding supports and said retaining posts.

It can be understood that said first portion of the second line is thusinclined and curved between said holder and guide device and thealready-wound or still-wound second line, and that it passes through theempty space between said retaining elements and said support elements,said space not being obstructed by a top plate.

For the rotary basket winding of the second line, the use of a pluralityof posts as winding supports presents less risk of the second line beingsubjected to excessive curvature since the flexible line is not undertension.

More particularly, in this third variant embodiment, the storage andhandling device comprises a single line guide and holder device suitablefor being moved vertically or horizontally at constant height to moverelative to a second support element of said flexible line guide andholder device, said second support element comprising a gantry.

This embodiment is the preferred embodiment of the flexible line storageand handling device since it makes it possible to avoid using twodistinct pieces of equipment or a single piece of equipment thatrequires major transformations that are difficult to perform on site, onthe open sea, in order to change between carousel mode winding androtary basket mode winding, thereby avoiding the ship being expensivelyheld up in port.

The embodiment referred to as being of the “mixed” type is alsopreferred since it makes it possible to optimize use of two flexiblelines of different diameters.

Flexible lines of smaller diameter are easier to wind as superposedturns in carousel mode since it is more difficult to arrange touchingturns of concentric increasing turn diameter on a plane in rotary basketmode with small-diameter lines.

Furthermore, flexible lines of relatively small diameter have a minimumradius of curvature that is also relatively small, thus enabling them tobe wound on a central cylinder of relatively small diameter, therebyachieving a corresponding increase in the maximum storage capacity incarousel mode in terms of the length of flexible line that can bestored.

Also preferably, in said third embodiment of the storage and handlingdevice of the invention, two flexible lines are wound on the mixedstorage and handling device comprising:

-   -   a said first line, preferably a first flexible pipe, of smaller        diameter wound on a said central cylinder in carousel mode; and    -   a flexible second line, preferably a second flexible pipe, of        greater diameter wound in rotary basket mode around said inner        posts.

Advantageously, said turntable is made up of two concentric portionscomprising:

-   -   an inner first turntable in the form of a disk suitable for        being driven in rotation; and    -   an outer second turntable of annular shape that is concentric        with said first turntable and arranged around said first        turntable, said second turntable being suitable for being held        stationary or for being driven in rotation together with said        first turntable when said first turntable is driven in rotation.

This embodiment is advantageous in that it serves to release an area ofdeck of varying size depending on the storage capacities in use of thestorage device.

Thus, the inner first turntable may be used in carousel mode, in basketmode, and in mixed mode, in which case the outer second turntable eitherhas no posts if the first turntable is used in carousel mode only, orelse it has only said retaining posts if said first and secondturntables are driven together in rotation as a unit and used in basketmode or in mixed mode, or else it has said retaining posts and saidinner winding support posts if the first and second turntables aresuitable for being driven together in rotation as a unit and used inbasket mode or in mixed mode.

In a first preferred embodiment, the top face of said turntable is planeand substantially at the same level as the plane of said deck aroundsaid turntable.

In another embodiment, the top of said turntable is conical in shape,preferably centered on the middle longitudinal axis XX′ of the ship,presenting a half-angle at the apex α greater than 95 grad, preferablyequal to 98 grad to 99 grad, more preferably a half-angle at the apex αof value substantially identical to the angle of inclination relative tothe vertical of said two plane portions P₁, P₂ of the deck of the ship,respectively sloping at a small angle β relative to the horizontal tostarboard P₂ and to port P₁ from a central ridge arranged said middleaxial longitudinal direction XX′ of the ship.

It can be understood that when said turntable is a double turntableconstituted by a said inner first turntable and a said annular secondturntable, said first turntable is conical in shape and the secondturntable is frustoconical in shape having the same half-angle at theapex.

Under all circumstances, each portion of said turntable, or whereappropriate each portion of said second turntable does not project, in adirection perpendicular to said plane, beyond the level of said plane ofthe deck closest to which it is juxtaposed, i.e. the plane of said deckthat is situated on the same side of said central ridge as saidturntable portion.

The present invention also provides, more particularly, a ship forlaying line at sea in accordance with the invention and furthercomprising a J-lay tower and at least one said flexible line woundaround a said storage and handling device including a holder and guidedevice for holding and guiding a line portion extending between saidholder and guide device and the wound line, said line including a curvedsecond line portion of catenary shape that is subjected to the tensionsolely of its own weight extending between said holder and guide deviceand a sheave arranged at a greater height on the tower, preferably atthe top of the tower, and a third line portion extending in rectilinearmanner within the tower being tensioned with the help of a secondtraction device secured to said J-lay tower and preferably of thecaterpuller type.

The means suitable for moving said first line portion vertically and/orhorizontally and extending between said holder and guide device and thealready-wound or still-wound line on said winding supports, depend onthe embodiment of the storage and handling device, and they may comprisethe following variants:

1) in a “rotary basket” type embodiment of the storage and handlingdevice: a motor and guide rails and/or slideways suitable for movingsaid holder and guide device horizontally along said rail and/orslideway that is horizontal and supported by a horizontal cross-beam ofa support gantry of said holder and guide device;

2) in a “carousel” type embodiment: a motor and vertical guide railsand/or slideways suitable for moving said traction device verticallyalong said rail and/or slideways supported by a post and/or a towercarrying said traction device;

3) in a “mixed” carousel and rotary basket embodiment: a motor suitablefor vertically moving a said horizontal transverse beam supported by atower or post of a gantry, and a motor suitable for horizontally movingsaid holder and guide device along said horizontal transverse beam; and

4) in all of the various “carousel”, “rotary basket”, and/or “mixed”embodiments, it is also possible to use auxiliary means such as hingedarms, suitable for moving said first line portion vertically and/orhorizontally and co-operating with a holder and guide device that isstationary and/or that is itself suitable for being moved verticallyand/or horizontally. Still more particularly, said flexible line is anundersea flexible line.

The present invention also provides a method of laying a flexible lineat sea from a ship of the invention, in which method the following stepsare performed:

1) moving the ship in a manner that is synchronized with the running ofthe line through said second traction device within the J-lay tower,preferably a said second caterpuller; and

2) unwinding said line by actuating in synchronized manner rotation ofsaid turntable, and moving said first line portion that extends betweensaid holder and guide device and the wound line in such a manner as tomaintain the curvature of said line portion extending between saidholder and guide device and said sheave arranged at a greater height onthe tower, with a catenary curve of curvature that is at all pointsgreater than the minimum curvature that is acceptable for the flexibleline, and preferably in such a manner that said catenary line portiondoes not touch the deck of the ship.

In a first implementation of the method of the invention, a saidflexible line wound in carousel mode is unwound by exertingsubstantially constant tension on said first line portion extendingsubstantially horizontally between the line holder and guide device andthe line wound on a said central cylinder with the help of a tractiondevice, preferably of the caterpuller type, and located at said lineholder and guide device.

It can be understood that this first implementation of the method can beperformed with a storage and handling device of the “carousel” type orof the “mixed” type.

In a second implementation of the method of the invention, a saidflexible line wound in rotary basket mode is unwound without exertingtension on said first line portion extending in an inclined positionbetween the line holder and guide device and the wound line, bysynchronizing the travel speed of the line with the help of a tractiondevice, preferably of the caterpuller type, and located at said lineholder and guide device, with the speed of rotation of said turntable.

It can be understood that this second implementation of the method ofthe invention may be performed with a storage and handling device of the“rotary basket” type or of the “mixed” type, as described above.

In a preferred implementation of the method of the invention, a mixedtype storage and handling device is used with:

-   -   a said first line, preferably a first flexible pipe, of smaller        diameter wound on a said central cylinder in carousel mode; and    -   a flexible second line, preferably a second flexible pipe of        larger diameter, wound in rotary basket mode on said inner posts        and retained by said peripheral retaining posts,

said method being characterized in that the following steps areperformed in succession:

1) unwinding and laying said second line at sea; then

2) removing said inner posts and said peripheral retaining posts; and

3) unwinding and laying said first line at sea.

It is necessary to remove the specific accessories of said rotary basketin order to enable said first line portion to be moved in verticaltranslation for the purpose of spooling it while unwinding it.

Conversely, in a method of storing two flexible lines by winding them ona “mixed” type storage and handling device, the following successivesteps should be performed:

1) winding said first line around said central cylinder in carouselmode;

2) mounting “rotary basket” type accessories comprising said inner andwinding support posts and said peripheral retaining posts; and

3) winding said second line around said inner winding support posts ofthe rotary basket, in rotary basket mode.

Other characteristics and advantages of the present invention appearbetter in the light of the following detailed description made inillustrative and non-limiting manner, and with reference to thedrawings, in which:

FIG. 1 is a side view of a laying ship fitted with a J-lay tower and astorage and handling device for a flexible line wound in a mode referredto as “carousel” mode;

FIG. 1A is a side view of various accessories of said carousel for beingsecured in releasable manner, i.e. in separable manner, to a turntableof a FIG. 1 storage and handling device, the accessories being installedon the deck of the laying ship and on said turntable, which turntable issubstantially in continuity with the plane of said deck;

FIG. 1B is a plan view of the turntable showing the means for attachingthe various accessories;

FIG. 1C is a side view of the deck of a ship including a turntable of astorage and handling device of the invention, said turntable beingsubstantially in the same plane as said deck;

FIG. 1D is a side view of said FIG. 1 carousel showing in detail thesequence for installing the various turns and layers of flexible line onthe cylinder of said carousel, while winding at the stage of windingfrom the last turn but one at the top of the third layer;

FIG. 2 is a side view of a laying ship fitted with a J-lay tower and astorage and handling device for a flexible line wound in a mode referredto as “rotary basket” mode;

FIG. 2A is a plan view of the FIG. 2 rotary basket type storage device;

FIG. 2B is a side view shown partially in section on the right-hand sideof a line AA of FIG. 2A, showing the sequence for placing the variousturns and layers of flexible line on the turntable constituting thebottom of the rotary basket type device at the stage of winding thesecond concentric turn of the third layer superposed on top;

FIG. 2C is a plan view of the spooler device 2 of a FIG. 2 rotary baskettype device, that is also capable of co-operating with a FIG. 1 carouseltype device 3, or indeed with a mixed device as described below withreference to FIGS. 3C and 3D;

FIGS. 3A, 3B, and 3C are side views, partially in section on the right,showing details of a preferred version of the invention describing amixed carousel and rotary basket storage and handling device in which afirst flexible line 7-1 is stored in carousel mode, being wound around acentral cylinder (FIGS. 3A, 3B, and 3C), and a second line 7-2 is storedin rotary basket mode against the periphery of said rotary basket, saidsecond line being wound around first intermediate posts or inner posts 9c forming second winding supports arranged around said first wound line(FIGS. 3B and 3C). In FIG. 3A, only the first line is shown being woundin carousel mode. In FIG. 3B, there are also shown the firstintermediate posts 9 c serving as a second winding support for a secondline in rotary basket mode while winding in rotary basket mode.Furthermore, in FIG. 3C, there is also shown the second line being woundin rotary basket mode on the accessories of the rotary basket, theperipheral posts 9 a serving as peripheral retaining posts for thesecond line;

FIG. 3D shows a mixed carousel and rotary basket type storage andhandling device having wound thereon a first line 7 ₁ in carousel mode,a second line 7 ₂ in rotary basket mode, and a third line 7 ₃ in rotarybasket mode;

FIG. 3E shows a central cylinder of a device of the invention fittedwith a top plate 3 b at the top of the central cylinder and with anintermediate circular plate 3 b′ surrounding said central cylinder,thereby enabling two first lines 7-1 a and 7-1 b to be wound thereon;

FIG. 4 is a side view of a laying ship fitted with a J-lay tower and aprior art device for storing and handling a flexible line of the typehaving motor drive that is movable on rails and suitable for fittingsuccessively to each of the drums installed in line one behind anotheron the deck of the ship;

FIG. 5 is a side view of a laying ship fitted with a J-lay tower, whilein operation laying rigid pipes, by assembling prefabricated stringstogether within said J-lay tower, said strings being stored on the deckof the ship on the turntable of a device of the invention after itsaccessories have been removed;

FIG. 6A is a plan view of an installation ship fitted with a turntablecentered on the middle longitudinal axis XX′ of the ship, the turntablehaving a diameter that is slightly less than the total width of saidship;

FIG. 6B is a plan view of an installation ship fitted with a doubleturntable installed offset to port relative to the middle longitudinalaxis XX′ of the ship;

FIG. 7A shows a plane turntable seen in vertical section, the turntablebeing centered on the longitudinal axis XX′ of the ship as shown in FIG.6A, the deck of the ship being constituted by two planes P₁ and P₂sloping at respective angles β to port P₁ and to starboard P₂ on eitherside of a central ridge running along the longitudinal direction XX′ ofthe ship; and

FIG. 7B is a vertical section view of a turntable having a top face Sthat is conical in shape and centered on the longitudinal axis XX′ ofthe ship, with a half-angle at the apex α corresponding to the slopeangle relative to the vertical of the two sloping planes respectively P₁to port and P₂ to starboard, constituting the deck 1 a of the ship.

FIG. 1 is a side view of a laying ship 1 fitted with a J-lay tower 12and a device for storing and handling a flexible line in a carousel typefirst embodiment 3. The device is constituted by a turntable 3 a drivento rotate about an axis Z₁Z₁′ perpendicular to said turntable byrotation means 3 a′ shown in FIG. 1C, and including motor drive 3 a′-1for imparting rotary drive to gearing 3 a′-2 at the periphery of saidturntable 3 a, said turntable 3 a being driven in rotation because itco-operates with a central rotary shaft 3 a′-5 on the same axis Z₁Z₁′and co-operating with wheels 3 a′-3 situated under said turntable andover a floor 3 a′-4 fastened to the load-carrying structure of the hulland of the deck of the ship, or “hull girder”.

In a manner known to the person skilled in the art, the portion 1 c ofthe hull girder outside the cavity 1 b comprises under the deck, and asshown in FIG. 1C:

-   -   main transverse structural elements or main “frames” 1 d;    -   secondary transverse structural elements or “bulb profiles” 1 g;        and    -   longitudinal primary beams 1 f.

Creating a cavity 1 b is known to the person skilled in the art, inparticular for creating a cavity that gives access from the deck to theholds of the ship.

In order to create the circular cavity 1 b, the portion 1 l of the hullgirder is configured within the cavity 1 b with lower additionalreinforcing elements 1 f, comprising:

-   -   main transverse reinforcing elements forming said frames 1 e and        secondary transverse reinforcing elements in the form of bulb        profiles 1 k under the floor 3 a-4 b that are closer to one        another in the longitudinal direction XX′ than are the frames 1        d and the bulb profiles 1 g in the portion 1 c of the hull        girder;    -   lower longitudinal beams 1 h also supporting said floor and the        rotation shaft 3 a′-5, that are closer to one another in the        transverse direction perpendicular to the longitudinal direction        XX′ than are the beams 1 l in the portion 1 c of the hull        girder;    -   the motor 3 a′-1 and gearing 3 a′-2 being fastened to structural        elements 1 c of the hull girder at the margin of the cavity        and/or to reinforcing elements 1 f within the cavity; and    -   the wheels 3 a′-3 being supported by said floor.

The wheels 3 a′-3 are interposed between the turntable 3 a and the floor3 a′-4, preferably on a plurality of circles of decreasing diameterabout the same vertical axis Z₁Z₁′ for the purpose of supporting theweight of the turntable, of the equipment, and of the flexible lines,and allowing the turntable 3 a to turn about the central axis ofrotation 3 a′-5. For clarifying the drawings, the various figures showonly one series of wheels 3 a′-3 distributed on a single circle ofdiameter substantially less than the outside diameter of said turntable.At the periphery of the cavity, the motor 3 a′-1 is fastened on atransverse frame 1 d or on a bulb profile 1 g supporting the deck andco-operates with a toothed system in gearing 3 a′-2 mounted on and/orco-operating with the periphery of said turntable 3 a in order to rotateit.

The turntable is then installed in said cavity above said wheels andfloor. The floor 3 a′-4 performs the same role as the deck plate 1 a interms of strength. The assembly is incorporated in the cavity 1 b in thedeck of the ship, as shown in FIG. 1C in such a manner that the topplane of said turntable is substantially at the same level as the deck 1a of said ship.

Thus, it is essentially the hull girder, i.e. the load-carryingstructure of the hull of the ship that serves to transfer all of thevertical loads from the turntable and its load, and also serves toprovide the rigidity needed for supporting the turntable and for loadingit.

On its top face, said turntable has attachment elements 4 a, 4 a-4 bserving to secure a variety of accessories that are described in greaterdetail in the following description of the invention. Said attachmentelements 4 are constituted, for example, by T-shaped grooves 4 a similarto those commonly used on machine tools, and as shown in plan view andin section view in FIG. 1B, or indeed mooring elements 4 b similar tothose used for stowing containers on board trucks or container carrierships, or finally, merely threaded holes drilled in the turntable forreceiving stowage lugs. Thus, when no accessory is installed on saidturntable, the deck of the ship is substantially plane and available fortransporting loads or for performing a variety of operations, such asthose shown in FIGS. 4 and 5, i.e. conventional laying of flexible linesof flexible pipe or electric cable type using winches 22 a-22 d withtheir axes of rotation parallel to the plane of the deck andperpendicular to the axis XX′ (FIG. 4A), or else laying rigid lines,e.g. by assembling successive strings together (FIG. 5), or indeedtransporting and handling all types of large-capacity andlarge-dimension structures, without any need to disassemble thecomponent elements of said turntable 3 a and of its supportingstructure, as is needed in the prior art.

In the carousel mode of the storage and handling device 3, accessoriesare installed on the turntable 3 a as shown in FIG. 1A. Theseaccessories comprise a first winding support element constituted by acylinder 3 c that is of tapering cylindrical shape or preferably ofright cylindrical shape of axis Z₁Z₁′ that preferably coincides with theaxis of said turntable 3 a, together with a top plate 3 b that ispreferably circular and that has the same vertical axis ZZ′. The topplate 3 b is secured to the top of the cylinder 3 c, with the base ofthe cylinder 3 c being secured to the turntable 3 a by the attachmentelements 4. A line 7 is wound around the cylinder 3 c between the topplate 3 b and the turntable 3 a that constitutes a bottom plate. A firstcaterpuller 5 with tracks or tires and known to the person skilled inthe art is arranged between the carousel type device 3 and the J-laytower 12, and it serves in known manner to exert tension on thehorizontal first portion 7 a of flexible line 7 that extends between thecaterpuller 5 and the last turn of the last layer of the wound line.This tension is adjusted so that said tension is maintained at asubstantially constant value, e.g. a tension of 5 t, so that the windingof said line on the carousel remains organized, as shown in FIG. 1D,i.e. so that the turns 7 i-1 to 7 i-l, with l=8, in each of thecylindrical layers 7 i with i=1 to 3 being concentric, and with eachbeing made up of superposed helical turns that remain stable andensuring that the set of turns does not collapse, which would lead toturns overlapping and/or would run the risk of severely damaging saidflexible line. While loading/winding the line on the carousel or whileunloading/unwinding the line, in order to ensure that the carousel typedevice 3 operates correctly, use is made of a spooler device 2 suitablefor moving the caterpuller 5 vertically along a support element 6extending in a direction Z₂Z′₂ perpendicular to said deck so that thefirst portion 7 a of the line that extends between the chain caterpuller5 and the device 3 always remains substantially horizontal. Said support6, installed to port, is constituted by a tower or post that is providedwith elements for guiding the caterpuller 5 and a motor drive 2 a, thebase of the post 6 being secured at 1 b′ to the deck 1 a of the shipclose to the carousel 3, preferably as close as possible. Thus, whileloading/winding the flexible line 7, 7-1 on said carousel 3, theturntable 3 a is rotated clockwise, and in conventional manner thevertical position of the first caterpuller 5 is adjusted so that thefirst portion 7 a of line between the caterpuller 5 and the carousel 3remains substantially horizontal and the turns 7 ₁-1 to 7 ₁-9 of linewind properly one above another, while remaining in intimate contactwith the preceding turns, as the first layer 7 ₁ closest to the centralcylinder rises, and then so that the turns 7 ₂-9 to 7 ₂-1 of line windone below another in juxtaposed manner against the central cylinder 3 cwhile building up the second layer 7 ₂ until reaching the turntable, andthen causing the caterpuller 5 to rise once more in order to wind thethird layer 7 ₃ of turns 7 ₃-1 to 7 ₃-9. Throughout the duration ofloading, tension is kept substantially constant, e.g. at 5 t by means ofthe caterpuller 5, so that each of the turns is positioned against thepreceding turn.

In FIG. 1D, the arrow shows the rising direction and then the fallingdirection and then once more the rising direction of the progression oflayers and 7 ₂, and respectively 7 ₃, and the turns 7 i-1 to 7 i-n withi=1 to 3 and n=9 during the loading of the flexible line 7 by beingwound onto the carousel 3.

More precisely, the first layer 7 ₁ is made starting from the bottomfirst turn 7 ₁-1 resting on the turntable 3 a up to the top last turn 7₁-9 beneath the top plate 3 b. Then, on reaching the top of the cylinder3 c, winding begins with an additional layer 7 ₂ starting from a firsttop turn 7 ₂-9 under the top plate 3 b and arranged beside and againstthe last top turn 7 ₁-9 of the first layer 7 ₁, and then continuing downto the bottom last turn 7 ₂-1 of the second layer that rests on theturntable 3 a against and beside the bottom first turn 7 ₁-1 of thefirst layer 7 ₁. Then, a third layer 7 ₃ is built up starting with afirst turn 7 ₃-1 placed against the turntable 7 ₂-1 resting on theturntable 3 a of the second layer 7 ₂ up to the top turn (not shown) ofthe third layer 7 ₃ under the top plate 3 b. As the first caterpuller 5moves up and down, its speed of upward and downward movement issynchronized with the speed of rotation of the turntable. Throughout theentire period of unwinding or winding the flexible line 7 from or ontothe carousel 3, said first caterpuller 5 is operated in a “constanttension” mode that is known to the person skilled in the art of winches.Thus, if the constant tension level is set for example at T₀=5 t, and ifthe tension tends to increase above the threshold set at T₀, thecaterpuller unwinds a certain length of line, thereby having the effectof bringing the tension down to T₀; likewise, if the tension tends todrop below the threshold set at T₀, the caterpuller winds in a certainlength of line, thus having the effect of returning the tension to T₀=5t.

More particularly, the first caterpuller 5 co-operates with hydraulicactuator motors associated with a thermal unit and adjusted in such amanner that said first caterpuller 5 exerts a said traction T₀ on theline portion 7 a. Thus, if the turntable 3 a turns so as to unwind theflexible line 7, the tension in the line portion 7 a decreases so thecaterpuller is automatically controlled to increase the tension that itexerts on the line portion 7 a by causing its tracks to turn, whichtracks rub against the line in such a manner that the resulting tensionexerted on the line portion 7 a by the first caterpuller is once moreT₀. Conversely, while winding, if as a result of the turntable 3 aturning the tension in the line portion 7 a exceeds the tension T₀ inthe line portion 7 a, the tracks of said first caterpuller 5 will turnin the opposite direction so as to move the line portion 7 a in thewinding direction, i.e. towards the carousel 3 so as to bring theresulting tension in the line portion 7 a to the value T₀ and allow theflexible line to be wound on the carousel 3. Throughout transport,tension is also maintained in the line portion 7 a, e.g. in the range 2t to 5 t, so as to avoid the tapering cylindrical assembly of line woundaround the cylinder 3 c collapsing. If this tension were not exerted,the last turns might tend to move away from the cylinder, therebycausing the following turns to drop since they would no longer be held.

The line 7, in its line portion 7 b that extends from the caterpuller 5to the top of the J-lay tower 12 adopts a catenary curve configuration.A sheave 8 of large size is installed on the hoisting ramp 2 a at thetop of the tower 12, said flexible line portion 7 b entering at 8 a intothe groove in said sheave 8 and the line portion 7 c leaving at 8 b,substantially on the laying axis of said tower 12. The flexible linethen passes through at least one second caterpuller 12 b within thetower, which maintains the line portion 7 c in suspension at 7 c-1 downto the sea bottom. Thus, during laying, the flexible line 7 is undermoderate tension in the portion 7 a, is substantially without tensionother than that generated by its own weight in the line portion 7 b ofcatenary shape, and is then subjected to the laying tension generated bythe second caterpuller 12 b in the portion 7 c by its own weight, saidlaying tension possibly being as much as 100 t to 150 t, or even morefor lines of large diameter in great depths of water.

The travel of the line while it is being unwound from the carousel 3 andwhile it passes through the tower 12 is adjusted so that the curvatureof the line portion 7 b remains between two limit curves 7 b-1 and 7 b-2so as to maintain the curvature of said line portion 7 b with curvaturethat is always greater than the minimum curvature that is acceptable atits junction with the sheave 8 or at its junction with the caterpuller5, i.e. curvature having a radius of curvature that is greater than theminimum acceptable radius of curvature for the line.

FIG. 2 is a side view of a laying ship 1 fitted with a J-lay tower 12and with a second embodiment of a storage and handling device 9 that isof a type referred to as a “rotary basket” device. Said rotary basket isshown partially in section on the right, and is constituted by saidturntable 3 a having a central cylinder 3 c placed thereon with avertical axis Z₁Z₁′ that coincides with the axis of the turntable 3 a. Aplurality of peripheral retaining posts 9 a are arranged at theperiphery of the turntable, they extend vertically and they arepreferably regularly distributed circularly about an axis Z₁Z₁′ thatcoincides with the axis of the turntable, said peripheral posts 9 apreferably being interconnected, e.g. at their tops, by a top rail 3 dof inside diameter that is preferably equal to or greater than thediameter of the circle that is tangential to the inside face of the setof posts 9 a. Thus, the top portion of the basket 9 is completely free,and it does not have a top plate at the top of the cylinder 3 c. Saidflexible line 7 is handled with the help of a spooler device 2 thatincludes a said first caterpuller 5 mounted on a support gantry 6 at afixed height relative to the deck 1 a of the ship and situated higherthan the top rail 3 d so that the line portion 7 a going to the cylinder3 c from the first caterpuller 5 slopes with a small amount of naturaland non-stressed curvature. Said gantry 6 is shown in FIGS. 2A and 2C;it comprises a horizontal cross-beam 6 b extending in the transversedirection YY′ and fastened on two vertical side posts 6 a, such thatfirst caterpuller 5 mounted on said cross-beam 6 b can move in thehorizontal direction YY′ under motor drive (not shown), therebyconstituting a device for performing horizontal spooling and suitablefor directing the first flexible line portion 7 a towards the cylinder 3c of the rotary basket in a direction that is kept permanentlysubstantially tangential to the turn that is being formed, as shown inFIG. 2A.

In this second embodiment of the “rotary basket” type, as shown in FIGS.2A and 2B, three superposed layers 7 ₁, 7 ₂, and 7 ₃ are thus formed,each comprising p=4 juxtaposed concentric turns 7 i-1 to 7 i-p with i=1to 3, the turns being one against another. More precisely, the firstlayer starts from a first turn 7 ₁-1 resting on the turntable 3 a andarranged against the periphery of the central cylinder 3 c, and then byturning the turntable and moving the caterpuller 5 along the cross-beam6 b, a second turn 7 ₁-2 is formed concentrically against the first turn7 ₁-1, and so on, until a fourth concentric turn 7 ₁-4 reaches theperiphery of the turntable 3 a on which it rests against the insidefaces of a series of peripheral posts 9 a attached to the turntable 3 aand serving to retain the various superposed layers 7 ₁, 7 ₂, and 7 ₃.When the first layer has been completed, the line comes into abutmentagainst the peripheral posts and can escape only by moving upwards,thereby naturally beginning the following layer. Thus, in order to makethe second layer 7 ₂, the layer starts with a peripheral turn 7 ₂-4arranged against the inside faces of the posts 9 a above the last turn 7₁-4 of the first layer, and then by moving the caterpuller 5 in theopposite direction horizontally along the cross-beam 6 b whilecontinuing to turn the turntable 3 a, a concentric turn 7 ₂-3 is formedof slightly smaller diameter and is placed against the inside face ofthe flexible line constituting the turn 7 ₂-4, and so on so as to makethe turn 7 ₂-2 and then 7 ₂-1 of decreasing diameters.

It can be understood that the retaining posts 9 a define the outermostposition of the turns 7 i-4 and, during loading, they make it possibleto begin the next layer up. These retaining posts 9 a also give theassembly a stable shape and in particular they ensure that the top layeris stable.

In this second embodiment of the storage and handling device 9 in rotarybasket mode, the first caterpuller 5 serves only to hold the flexibleline 7 so that the first and second line portions 7 a and 7 b adopt acertain amount of curvature without exerting significant tension in thefirst line portion 7 a between said first caterpuller 5 and the rotarybasket device 9, in contrast to what happens with the carousel typefirst embodiment of the device 3.

In FIG. 2B, the direction in which loading is performed by winding layerafter layer is shown in side view, showing how the turns progress andhow the layers progress in this rotary basket type second embodiment ofthe storage and handling device 9, with each layer in this examplehaving four turns. When the line 7 is taken to the rotary basket 9 forwinding the line, or when the flexible line 7 is extracted from therotary basket 9 for unwinding and laying at sea, the rotation of theturntable and the movement in translation of the spooler device in thehorizontal direction are synchronized as is the speed of rotation of thetracks of the first caterpuller 5 in such a manner that the curvaturesof the curves 7 a and 7 b remain acceptable, and in particular continueto have a radius of curvature that is greater than the minimum radius ofcurvature that is acceptable for the line.

As shown in FIG. 2A, during installation on site, the first caterpuller5 is actuated to unwind and extract the flexible line 7 from the rotarybasket type device 9 and direct it towards the sheave 8 on the tower 12,and then towards the second caterpuller 12 b. Thus, only the portion 7 cextending beneath the second caterpuller 12 b is subjected to a largeamount of laying tension, and the other two line portions 7 a and 7 bare subjected only to low levels of handling tension, i.e. to tensionsof a few tonnes, or even less.

FIG. 3C is a side view of a first variant of a mixed carousel and rotarybasket embodiment of the storage and handling device 20 of theinvention. In this variant embodiment, a tapering cylinder 3 c and a topplate 3 b of outside diameter smaller than the diameter of the turntable3 a are installed initially, with said diameter of the top plate 3 bbeing greater than the diameter of the last layer 7 ₃ of the first line7-1 in carousel mode as described above with reference to FIGS. 1 and 1Ato 1D for storing in carousel mode. Thereafter, a first line 7-1 isstored by being wound on the device in carousel mode around a centralcylinder 3 c arranged coaxially with said turntable 3 a, as shown inFIG. 3A. After the first flexible line 7-1 has been loaded/wound, theaccessories are installed for transforming the device into rotary basketmode as follows. Installation comprises, in succession, installing afirst series of posts in an intermediate position, referred to as “innerposts” 9 c that are preferably distributed uniformly and circularly andthat are preferably secured via their bases to attachment elements onthe turntable 3 a and via their tops to the top of the cylinder 3 c viathe outside of the top plate 3 b. Said intermediate first set of postscan then act as the second winding support equivalent to the cylinder ofthe rotary basket type device 9 of FIG. 2 while winding a second line7-2. Thereafter, a series of peripheral retaining posts 9 a is installedthat are arranged in the manner described above at the periphery of theturntable 3 a, being secured via their bases to attachment elements 4 ofthe turntable 3 a and preferably being connected to one another at theirtops by a circular rail 3 d. The second flexible line is thenloaded/wound in rotary basket mode, as described above with reference toFIGS. 2 and 2A and 2C.

Said peripheral posts 9 a are preferably distributed regularly along thecircular periphery of the turntable 3 a, and the inner posts 9 c arelocated close to the peripheral last layer 7 ₃ of the first line 7-1wound on the cylinder 3 c.

Thereafter, a second flexible line 7-2 is stored by being wound inrotary basket mode. To do this, the first turn 7 ₁-1 of the first layer7 ₁ of the second line 7-2 is wound against the outside face of theinner posts 9 c of the winding support for the second line 7-2, and thenas described for the rotary basket mode, the second and third concentricturns 7 ₁-2 and 7 ₁-3 are wound that are juxtaposed side by side untilreaching the inside faces of the peripheral posts 9 a, after which thesecond layer 7 ₂ is wound, being made up of turns 7 ₂-3, 7 ₂-2, and then7 ₂-1 going respectively from the peripheral retaining posts 9 a towardsthe winding supports or inner posts 9 c, followed by the third layer 7 ₃as described above going from the inner posts 9 c towards the retainingposts 9 a. To unwind the lines and lay them, it is appropriate to beginwith unwinding and laying the second line 7-2 in rotary basket mode,after which the specific accessories should be removed from the rotarybasket, i.e. the inner posts 9 c and the peripheral retaining posts 9 a,in order to unwind and lay the first line 7-1 in carousel mode.

This disassembly is necessary, since otherwise the first line portion 7a leaving the device in carousel mode would not be able to extendhorizontally while it is being spooled, since said intermediate posts 9c and retaining posts 9 a would prevent it.

In FIG. 3D, there can be seen a second variant embodiment of a mixedcarousel and rotary basket device 20 of the invention. A first flexibleline 7-1 is stored initially in carousel mode on a central cylinder 3 cas described above. Thereafter, two respective series of first andsecond intermediate posts 9 c and 9 b are installed. The series of firstintermediate posts 9 c is distributed on a circle of radius R1, theseries of second intermediate posts 9 b being distributed on a secondcircle of radius R2 greater than R1. It is thus possible in rotarybasket mode to load a second flexible line 7-2 against said firstintermediate posts or inner posts 9 c out as far as said secondintermediate posts 9 b acting as retaining posts for said second line7-2. In FIG. 3D, the second line 7-2 is wound against the inner posts 9c in five superposed layers, each comprising one helically arrangedturn. The second intermediate posts 9 b serve as a third winding supportfor a third line 7-3, which is shown in FIG. 3D as having three layers 7₁ to 7 ₃, each of two juxtaposed concentric turns 7 _(i)-p with i=1 to 3and p=1 or 2. The third line 7-3 is loaded by winding in rotary basketmode, but only after installing the peripheral retaining posts 9 a thatserve to return the third flexible line 7-3.

While laying said line at sea, it is necessary to begin by unwinding andlaying either of the second or third lines 7-2 or 7-3 in either order.It should be observed that if the second and third lines 7-2 and 7-3were stored one after the other, i.e. one above the other in the samecompartment between said inner posts 9 c and said peripheral retainingposts 9 a, then it would be necessary to unload and lay the line thatwas wound last, i.e. the top line. It would then not be possible todecide which line to lay, as is made possible by a mixed device having aplurality of series of intermediate posts as in the invention. In FIG.3D, two series of intermediate posts 9 c and 9 b are used. Nevertheless,it is possible advantageously to use as many series of intermediateposts as needed as a function of the number of lines to be stored so asto retain the greatest possible flexibility for laying lines on site. Inany event, it is appropriate to unwind and lay all of the lines that arestored in rotary basket mode before beginning to unwind and lay thefirst line that is wound in carousel mode, after removing the innerposts 9 c and the various intermediate and peripheral retaining posts 9b and 9 a.

In FIG. 3E, there can be seen a variant embodiment in which the centralcylinder is fitted with a top circular plate 3 b at its top and issurrounded by an intermediate circular plate 3 b′ having the samediameter and located halfway up, thus making it possible to wind a firstline 7-1 a from the turntable 3 a up to immediately under the bottomface of the intermediate plate 3 b′, and then to wind a second firstline 7-1 b from the intermediate plate 3 b′ up to and immediately underthe face of the top plate 3 b. Under such circumstances, the two firstlines 7-1 a and 7-1 b can be wound/unwound in either order.

FIG. 4 is a side view of conventional laying of flexible lines 7 ingreat depth from a series of horizontal-axis winches or drums 22 a-22b-22 c-22 d having flexible line portions wound thereon. A drum driveunit 20 is suitable for sliding on rails 21 and for being fitted insuccession to each of the drums 22 a-22 b-22 c-22 d in order to lifteach one of them individually and in order to put them into rotation insuccession so as to unwind the various flexible line portions 7 thathave been wound onto the drums. Thus, when the first drum 22 a having aline wound thereon has been unwound, the end of said line 7 is madesecure. Then the empty drum 22 a is put back on its support 22-1 and thedrum motor drive 20 is moved to the following drum 22 b and the end ofthe line wound on the second drum 22 b is connected to the secured endof the flexible line that has already been laid. Thereafter, laying offlexible line continues by unwinding the various flexible line portionson the various following drums 22 c-22 d. This type of drum 22 a-22 bgenerally presents a diameter lying in the range 8 m to 12 m and a widthlying in the range 5 m to 8 m, however it is capable of storing only alimited length of line portion, and the loaded drum may then weigh asmuch as 350 t to 750 t, or even more.

By comparison, storage in carousel mode as shown in FIG. 1 and FIGS.3A-3D is advantageous when laying lines of very great length, since itmakes it possible to store lines of greater length and/or of greaterdiameter, while avoiding the problems of connecting lines together asare encountered when line is stored as a plurality of segments on aplurality of drums. With flexible lines of large diameter, conventionalstorage on winches as shown in FIG. 4 is often not possible since theminimum radius of curvature of said flexible line is very large,typically up to 5 m or more, which would require drums 22 a-22 d of verylarge size that would then be unsuitable for handling. Storage in rotarybasket mode as shown in

FIGS. 2 and 3C-3D is much better adapted to lines of large diameter witha large minimum radius of curvature, since it enables long unit lengthsthereof to be stored without running the risk of a radius of curvaturethat is less than the minimum radius of curvature. Mixed storage asdescribed with reference to FIGS. 3A to 3C is preferred since that makesit possible to use carousel mode against the central cylinder 3 c tostore a long length of first line 7-1 of small or medium diameter, andto store peripherally around said inner posts 9 c and secondintermediate posts 9 b a second line 7-2 or indeed a third line 7-3 oflong length and large diameter in rotary basket mode. The diameter ofthe circle along which the inner posts 9 c are placed to constitute thesupport element for winding the second line in rotary basket mode in themixed device must be greater than the minimum diameter of curvature ofsaid second flexible line 7-2, even though the central cylinder 3 cpresents a diameter that is too small and thus incompatible with storingsuch a large diameter line 7-2. This winding technique of the rotarybasket type is thus advantageous for flexible lines that are long and oflarge diameter and that cannot be wound on a cylinder of small diameter,given a minimum radius of curvature that is too great.

It is possible to wind lines of small or medium diameter, less than 200mm over lengths of 1 km to 200 km on a cylinder 3 c having a diameter of1 m to 15 m and a height of 3 m to 10 m, using a carousel type device ofsmall or medium diameter. It is also possible with a rotary basket typedevice to wind lines of larger diameters, in particular diametersgreater than 200 mm and for lengths that also exceed 1 km, with thecircle of inner posts 9 c presenting a diameter greater 8 m, and inparticular lying in the range 12 m to 30 m.

By way of example, a turntable 3 a having a diameter of 30 m and capableof supporting a load of 5000 t can be used to store a line over a heightof 6 m as follows:

-   -   in carousel mode: 150 km of electric cable having a diameter of        150 mm and a weight per unit length of 25 kilograms per meter        (kg/m), i.e. about 76 layers of 40 turns representing a total        weight of about 4000 t;    -   in rotary basket mode: 12.5 m of flexible line having a diameter        of 500 mm, a weight per unit length of 350 kg/m and a minimum        radius of curvature R=5 m, giving about 12 layers of 18 turns,        representing a total weight of about 4500 t;    -   in mixed mode as shown in FIG. 3C:        -   in carousel mode: 10 km of umbilical 7-1 having a diameter            of 200 mm and a weight per unit length of 45 kg/m, i.e.            about 15 layers of 30 turns, representing a total weight of            about 450 t; plus        -   in rotary basket mode: 18.5 km of flexible line 7-2 having a            diameter of 400 mm, a weight per unit length of 200 kg/m and            a minimum radius of curvature R=6 m, i.e. about 15 layers of            20 turns, representing a total weight of about 3700 t,            together giving a total weight of about 4150 t; and    -   in the mixed mode of FIG. 3D:        -   in carousel mode: 22.5 km of umbilical 7-1 with a diameter            of 100 mm and a weight per unit length of 15 kg/m, i.e.            about 20 layers of 60 turns, representing a total weight of            about 350 t; plus        -   in rotary basket mode in a first circular corridor having a            cylinder diameter D1=10 m and a width of 1 m: 850 m of            flexible line having a diameter of 400 m, a weight per unit            length of 180 kg/m, and a minimum radius of curvature R=4 m,            i.e. about 13 layers of two turns, representing a total            weight of about 160 t; plus        -   in rotary basket mode in a second circular corridor having a            cylinder diameter D2=14 m and a width of 3 m: 3900 m of            flexible line having a diameter of 450 mm, a weight per unit            length of 300 kg/m, and a minimum radius of curvature R=4 m,            i.e. about 13 layers of six turns, representing a total            weight of about 1200 t; plus        -   in rotary basket mode in a third circular corridor having a            cylinder diameter D3=22 m and a width of 2.5 m: 3900 m of            flexible line having a diameter of 600 mm, with a linear            weight of 450 kg/m and a minimum radius of curvature R=6 m,            i.e. about ten layers of five turns representing a total            weight of about 1800 t, the entire weight then coming to            about 3510 t.

FIG. 6A shows a turntable 3 a with a diameter of 30 m and a capacity of8000 t installed on the axis of the deck of an installation ship, nearthe bow.

FIG. 6B shows a double turntable 3 a with a diameter of 20 m and acapacity of 4500 t installed on the deck of an installation ship nearthe bow, said double turntable 3 a being offset to port so as to leave afree passage on the starboard side when said turntable is fitted incarousel mode, in rotary basket mode, or in mixed mode. The doubleturntable is constituted by an inner first turntable 3 a-a of diameterφ₁ that is in the shape of a disk, and an outer second turntable 3 a-bthat is annular in shape and arranged concentrically around said firstturntable, independently of said first turntable, with an outsidediameter such that φ₂>φ₁. The two turntables lie in the same plane andsubstantially in the same plane as the deck of the ship. Motor driveacts on the inner turntable 3 a-a and the second turntable 3 a-b caneither be held stationary while the first turntable is being driven inrotation, or else it can be secured thereto and driven in rotationtogether with said first turntable, or else it may be suitable for beingdriven in rotation independently of said first turntable, depending onthe desired storage capacity. Thus, for storage of maximum capacity, thefirst and second turntables are secured to each other and a maximumstorage capacity having a diameter φ₂ is available. If it is desired touse a smaller capacity, said second turntable is left stationary, beingsecured directly to the deck of the ship, and the first turntable isdriven in rotation so as to make available only a smaller capacitycorresponding to the diameter φ₁ of the first turntable 3 a-3. Theadvantage of this arrangement lies in the free passage on the deck ofthe ship beside the device which then corresponds to a wide corridor ofwidth L₂ when it is desired to use only said first turntable 3 a-a,whereas the corridor is only of smaller width L₁ when the device is usedto its maximum capacity, corresponding to the first and secondturntables taken together. The wider corridor then enables additionalequipment to be installed, and that constitutes a major advantage innumerous installation operations on oil fields at sea, because of theflexibility of the device.

For conventional line laying operations using 50 m long strings of rigidline 10 made up of unit lengths of line 11 stored on the deck of theship and with a J-lay type tower 12, it is possible to remove saidaccessories 3 c-3 b, 9 a-9 b-9 c, and to leave the turntable 3 a inposition, as shown in FIG. 5, since it is level with the deck andtherefore does not interfere with the equipment that is put into placethereon.

The fact that the turntable 3 a is integrated in a cavity 1 b makes itpossible to avoid a potential large loss of time should it be necessaryto remove the turntable 3 a in order to release space on the deck 1 a.

Because the turntable is incorporated in the hull so as to be continuouswith the plane of the deck, there is no need for it to be removed whenit is desired to use the deck for other installations, thereby avoidingany need to take the boat out of operation for several days in port inorder to perform this operation, and thus constituting a large economicadvantage.

The deck 1 a of a ship generally presents two planes P₁ and P₂ that areat a gentle slope β relative to the horizontal, of less than 5%, and inparticular in the range 1% to 2%, to port P₁ and to starboard P₂ runningfrom a central axial ridge XX′ so that rain water or spray is directedto the sides of the ship for running off into the sea: such a decktherefore does not constitute a plane as such. Thus, said turntable ispreferably plane and installed in such a manner that it does not projectat any point beyond said deck of the ship, as shown in FIG. 7A. Thus,when it is not in use, there will exist a small offset in certainregions of the deck between said deck and said turntable, which offsetcan be compensated by wedges, e.g. wooden wedges, said wedges restoringsurface continuity to the deck so as to enable the required equipment tobe installed thereon. This local wedging is of thickness that variesdepending on position and that lies in the range 20 mm to 200 mm-300 mmdepending on the diameter of the turntable and the structure of the deckof the ship.

Nevertheless, it is advantageous to make a turntable that is not planebut that is slightly conical as shown in FIG. 7B with a half-angle α atthe apex that coincides with the angle of inclination of the planes P₁and P₂ of the deck of the ship to port and to starboard relative to avertical axis perpendicular to said axial central ridge XX′, i.e. anangle α of more than 95 grad or an angle β of less than 5 grad, moreparticularly an angle β in the range 1 grad to 2 grad, i.e. a half-angleat the apex α of the cone of 98 grad to 99 grad. Such a conicalturntable should then preferably be installed on the axis of the ship asshown in FIG. 6A and in FIG. 7B. In FIG. 7B, the conical turntable isarranged in such a manner that the portions of said turntable that aresituated on either side of said central ridge XX′ do not project beyondthe plane P₁ or P₂ of the deck situated on the same side of the centralridge XX′ in a direction that is perpendicular to said plane of thedeck, and the apex of said turntable does not project vertically abovethe central ridge XX′ of said deck. In other words, said planes P₁ andP₂ on the port and starboard sides respectively of said deck aretangential to each of the portions of said turntable arranged on thesame side, respectively as said port plane P₁ or said starboard planeP₂.

A turntable of the invention is typically made of steel presenting adiameter lying in the range 5 m to 50 m and a thickness lying in therange 100 mm to 800 mm. A central cylinder 3 c may be made ofmachine-welded sheet metal presenting a height lying in the range 3 m to10 m with a diameter of 1 m to 10 m in carousel mode and 5 m to 15 m inrotary basket mode.

The post or gantry 6 carrying the caterpuller and the spooler systemshould be positioned as close as possible to the outside of the topplate 3 b of the carousel and in practice within less than 5 m, and morepreferably within less than 1 m.

The turntable 3 a should be positioned on the deck at a distance fromthe J-lay tower 12 that is sufficient to ensure that the radius ofcurvature of the line is greater than at least three times the minimumradius of curvature that the line can accept in the portion 7 bextending from said caterpuller to the top of the tower. Thus, theturntable 3 a should be arranged closer to the end of the ship that isremote from the tower than to the tower.

In an embodiment, the laying ship is not fitted with a laying tower, butwith a chute, generally situated at the stern of the ship. This appliesin particular for laying lines in shallow waters, in particular atdepths of less than 500 m.

In an embodiment, in order to perform spooling so that the flexible lineis always tangential on reaching the turn that is currently being woundor unwound, it is preferable to avoid moving the caterpuller and ratherto make it co-operate with guide means such as a chute and a hinged armsuitable for moving laterally and thus in the transverse direction YY′(rotary basket mode=horizontal spooling) of the ship or in the verticaldirection ZZ′ (carousel mode=vertical spooling).

Constant tension devices, whether using tracks or tires, and spoolingsystems for winches and rotary baskets are known to the person skilledin the art, and in particular they are sold by the supplier Huisman(Netherlands).

1-18. (canceled)
 19. A laying ship for laying flexible undersea lines atsea, the ship having a deck including a cavity having arranged thereinsaid turntable and a motor-driven support and rotation device for thecircular turntable, the top face of said circular turntable notprojecting significantly beyond the level of the portion of the deckthat is immediately juxtaposed laterally thereto, the periphery of saidturntable coming level with said deck, said turntable being supported byand co-operating in rotation with elements of the support and rotationdevice within said cavity and fastened to the carrier structure of thehull of the ship, said rotary turntable presenting attachment elementson its top face and suitable for enabling flexible line winding supportsof a flexible line storage and handling device to be reversibly attachedthereto, said winding supports extending in a direction ZZ′perpendicular to and above said plane of the deck of the ship, saidattachment elements being distributed circularly and at different radialdistances from the vertical central axis of rotation Z₁Z₁′ of saidturntable.
 20. The laying ship according to claim 19, wherein saidcarrier structure of the hull includes additional reinforcing elementsin said cavity, and said support and rotation device within said cavitycomprises: a floor fastened to and supported by said additionalreinforcing elements of said carrier structure of the hull under saidfloor; rotary guide elements supported by said floor and a rotary shaftsupported by additional reinforcing elements of said carrier structureof the hull under said floor; and a motor and rotary drive elements fordriving the turntable and said rotary shaft in rotation by actuatingsaid motor, the elements being supported by said carrier structure ofthe hull within and at the periphery of said cavity.
 21. The laying shipaccording to claim 20, wherein said attachment elements comprise groovesand/or holes arranged radially and circularly over the surface of theturntable.
 22. The laying ship according to claim 19, wherein saidlaying ship supports a modular storage and handling device for storingflexible line by winding and unwinding the flexible line, the devicecomprising: a) said turntable supporting said accessories on its topface, which accessories are reversibly attached to said attachmentelements, said accessories thus forming one or more winding supportsextending in the perpendicular direction ZZ′ and above said plane ofsaid deck of the ship, said winding supports being arranged circularlyrelative to the central axis of rotation Z₁Z₁′ of said turntable on thetop face of said turntable; and b) a spooler device comprising aflexible line guide and holder device mounted on a second supportelement forming a post, a tower, or a gantry extending at least in adirection perpendicular to and above the deck of the ship in theproximity of said turntable and including motor-driven means for movinga first flexible line portion extending between said guide and holdingdevice and said storage and handling device, and suitable for enablingvertical and horizontal movement of said flexible line portion relativeto said second support element in order to enable said flexible line tobe spooled around and against said winding supports.
 23. The laying shipaccording to claim 22, wherein the flexible line storage and handlingdevice is of the type referred to as the “carousel” type and comprising:a) the winding support having a continuous wall in the form of atapering or right central cylinder arranged coaxially about the axis ofsaid turntable, said cylinder being surmounted by at least one topcircular plate at its top; and b) the spooler device suitable forspooling said flexible line around and against said central cylinder insaid “carousel” mode, comprising a line traction device suitable fortensioning said first line portion extending between said tractiondevice and the already-wound or still-wound portion of line, and meanssuitable for moving said tensioned first flexible line portionvertically in such a manner as to keep it substantially horizontal whileit is being wound or unwound so as to enable the line to be spooled in aplurality of coaxial layers of touching turns and enabling it to beunwound, said flexible line thus being wound or being suitable for beingwound in “carousel” mode in a plurality of layers such that the turns ofany one layer are helically superposed, the various layers formingjuxtaposed coaxial cylindrical columns.
 24. The laying ship according toclaim 22, wherein the flexible line storage and handling device is ofthe type known as the “rotary basket” type, comprising: a) said one ormore winding supports comprise a plurality of winding supports in theform of inner posts arranged circularly relative to the axis of rotationZ₁Z₁′ of said turntable or a tapering or right central cylinder arrangedon the axis with said turntable, and peripheral retaining elementsextending in the perpendicular direction ZZ′ above said deck of theship, being disposed circularly relative to the central axis of rotationZ₁Z₁′ of said turntable on the top face of said turntable; and b) saidspooler device suitable for spooling said flexible line around andagainst said central cylinder or said plurality of inner posts in“rotary basket” mode comprising a line holder and guide device, andmeans suitable for moving the first flexible line portion in atransverse direction YY′ perpendicular to said vertical central axis ofrotation Z₁Z₁′, the first flexible line portion extending in an inclinedposition between said holder and guide device and the already-wound orstill-wound line, so as to enable the line to be spooled as a pluralityof superposed layers of touching turns and so as to enable it to beunwound, the flexible line thus being wound or being suitable for beingwound in “rotary basket” type mode as a plurality of superposed layerssuch that the turns in any one layer are juxtaposed concentrically,lying on a common plane and presenting diameters that increase from thefirst turn pressed against the winding support(s) out to the last turncoming into abutment against said peripheral posts, said line portionextending between the holder and guide device and the already-wound orstill-wound line without being tensioned by said holder and guidedevice, which is held at constant height above the top ends of saidwinding supports and said retaining posts.
 25. The laying ship accordingto claim 22, wherein the flexible line storage and handling device is ofthe mixed carousel and the rotary basket type suitable for storing andhandling at least two flexible lines and comprising: a first windingsupport for a first line, said first winding support having a continuouswall in the form of a tapering or right central cylinder arrangedcoaxially about the axis of said turntable; a plurality of secondwinding supports for winding a second line, the supports being in theform of inner posts arranged circularly relative to the central axis ofrotation Z₁Z₁′ of said turntable at a constant radial distance from saidcentral cylinder; peripheral retaining elements in the form of postsextending in the perpendicular direction ZZ′ above said plane of saidship deck, arranged circularly relative to the central axis of rotationZ₁Z₁′ of said turntable; said central cylinder being surmounted by a topcircular plate at its top and of diameter such that said inner windingposts of the second line are secured to one another at their tops bybeing fastened to the periphery of said top plate, said first and secondsupport elements and said retaining elements being arranged on the topface of said turntable; the spooler device including at least a secondsupport element for supporting at least one flexible line guide andholder device suitable for enabling a said first flexible line portionto be moved vertically and horizontally, the first flexible line portionextending between the guide and holder device and the already-wound orstill-wound line for spooling said flexible line around and against saidwinding supports, said second support element forming a tower or agantry extending at least in a direction ZZ′ perpendicular to the planeof said and above said bridge, in the proximity of said turntable; saidflexible line guide and holder device being suitable for enabling afirst flexible line to be spooled around and against said centralcylinder in “carousel” mode and comprising a line traction devicesuitable for tensioning the first line portion extending between thetraction device and the already-wound or still-wound first line, saidtraction device being a caterpuller, and means suitable for verticallymoving said first flexible line portion extending between the tractiondevice and the already-wound or still-wound first line so that it can betensioned and held substantially horizontally by said traction device toenable the first line to be spooled as a plurality of coaxial layers ofsuperposed touching turns, said first flexible line thus being wound orbeing suitable for being wound as a plurality of coaxial layers suchthat the turns in any one layer are superposed helically, the variouslayers forming juxtaposed coaxial cylindrical columns such that twoturns of two juxtaposed layers present different diameters; and saidflexible line guide and holder device also being suitable for enabling asecond flexible line to be spooled around and against said windingsupports in the form of inner posts in “rotary basket” type mode,comprising a traction device for applying traction to the line,constituted by a caterpuller, and means suitable for moving said portionof the second flexible line in horizontal translation in a transversedirection YY′ perpendicular to said central axis of rotation Z₁Z₁′, saidfirst portion of the second flexible line extending in an inclinedposition between the holder and guide device and the already-wound orstill-wound second line in order to enable said second line to bespooled as a plurality of superposed layers of touching turns, saidsecond flexible line thus being wound or being suitable for being woundas a plurality of superposed layers such that the turns in any one layerare concentrically juxtaposed, resting on a common plane and havingdiameters that increase from the first turn pressed against said windingsupports in the form of inner posts to the last turn coming intoabutment against said peripheral retaining posts, said first portion ofthe second line not being tensioned by said holder and guide device,which is held at a constant height above said winding supports and saidretaining posts.
 26. The laying ship according to claim 25, wherein thelaying ship has a single line guide and holder device suitable for beingmoved vertically or horizontally at constant height to move relative toa second support element of said flexible line guide and holder device,said second support element comprising a gantry.
 27. The laying shipaccording to claim 25, wherein two flexible lines are wound on a mixedstorage and handling device comprising: a first line of smaller diameterwound on a said central cylinder in carousel mode; and a flexible secondline of greater diameter than the diameter of said first line and woundin rotary basket mode around said inner posts.
 28. The laying shipaccording to claim 25, wherein said turntable is made up of twoconcentric portions comprising: an inner first turntable in the form ofa disk suitable for being driven in rotation; and an outer secondturntable of annular shape that is concentric with said first turntableand arranged around said first turntable, said second turntable beingsuitable for being held stationary or for being driven in rotationtogether with said first turntable when said first turntable is drivenin rotation.
 29. The laying ship according claim 19, wherein the topface of said turntable is plane and substantially at the same level asthe plane of said deck around said turntable.
 30. The laying shipaccording to claim 19, wherein the top face of said turntable is conicalin shape, centered on the middle longitudinal axis XX′ of the ship,presenting a half-angle at the apex α greater than 95 grad, ofhalf-angle at the apex α of value substantially identical to the angleof inclination relative to the vertical of said two plane portions P₁,P₂ of the deck of the ship, respectively sloping at a small angle βrelative to the horizontal to starboard P₂ and to port from a centralridge arranged said middle axial longitudinal direction XX′ of the ship.31. The laying ship according to claim 19, wherein said ship furtherincludes a J-lay tower and at least one said flexible line wound arounda said storage and handling device including a holder and guide devicefor holding and guiding a line portion extending between said holder andguide device and the wound line, said line including a curved secondline portion of catenary shape that is subjected to the tension solelyof its own weight extending between said holder and guide device and asheave arranged at a greater height on the tower, and a third lineportion extending in rectilinear manner within the tower being tensionedwith the help of a second traction device secured to said J-lay tower.32. The laying ship according to claim 19, wherein said flexible line isan undersea flexible line.
 33. A method of laying a flexible line at seafrom a ship according to claim 31, the method wherein the followingsteps are performed: 1) moving the ship in a manner that is synchronizedwith the running of the line through said second traction device withinthe J-lay tower; and 2) unwinding said line by actuating in synchronizedmanner rotation of said turntable, and moving said first line portionthat extends between said holder and guide device and the wound line insuch a manner as to maintain the curvature of said line portionextending between said holder and guide device and said sheave arrangedat a greater height on the tower, with a catenary curve of curvaturethat is at all points greater than the minimum curvature that isacceptable for the flexible line, and preferably in such a manner thatsaid catenary line portion does not touch the deck of the ship.
 34. Themethod according to claim 33, wherein a said flexible line wound incarousel mode is unwound by exerting substantially constant tension onsaid first line portion extending substantially horizontally between theline holder and guide device and the line wound on a said centralcylinder.
 35. The method according to claim 33, wherein a said flexibleline wound in rotary basket mode is unwound without exerting tension onsaid first line portion extending in an inclined position between theline holder and guide device and the wound line, by synchronizing thetravel speed of the line with the speed of rotation of said turntable.36. The method according to claim 33, wherein a storage and handlingdevice of mixed type is used with: a first line of smaller diameterwound on a said central cylinder in carousel mode; and a flexible secondline wound in rotary basket mode on said inner posts and retained bysaid peripheral retaining posts, said method wherein the following stepsare performed in succession: 1) unwinding and laying said second line atsea; then 2) removing said inner posts and said peripheral retainingposts; and 3) unwinding and laying said first line at sea.